Magazine cartridge feed for semiautomatic firearms



MAGAZINE CARTRIDGE FEED FOR SEMIAUTOMATIC FIREARMS Filed March 4, 1960 A. J. PANZICA May 2, 1961 2 Sheets-Sheet 1 MAGAZINE CARTRIDGE FEED FOR SEMIAUTOMATIC FIREARMS Filed March 4, 1960 A. J. PANZICA May 2, 1961 2 Sheets-Sheet 2 INVENTOR. Arfihgly J P11nzi\:u

United States Patent MAGAZINE CARTRIDGE FEED FOR SEMIAUTO- MATlC FIREARMS Anthony J. Panzica, Northampton, Mass., assignor to the United States of America as represented by the Secretary of the Army Filed Mar. 4, 1960, Ser. No. 12,875

Claims. (CI. 89-33) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to shoulder firearms capable of firing relatively large, heavy projectiles and is more particularly directed to automatic means for successively positioning these projectiles in the firearm for semiautomatic discharge therefrom.

In firearms adapted to discharge unusually large projectiles, such as grenades, semiautomatic operation thereof has not proven feasible due to the difficulties presented in providing clips for magazines capable of successively advancing a plurality of bulky rounds into firing position. While the use of springs for advancing the cartridges held in conventional box or tubular magazine structures may be satisfactory for semiautomatic firearms of smaller caliber, the increased loads required to move relatively large projectiles into firing position introduce the possibility of damage thereto.

It is, therefore, an object of this invention to provide means for automatically feeding relatively large rounds into a shoulder-operated firearm without the necessity for moving the individual rounds relative to one another.

It is a further object of this invention to provide a magazine for automatically feeding relatively large and heavy rounds into a shoulder-operated firearm wherein the chambers in which the rounds are fired are incorporated in the magazine itself.

Still another object of this invention lies in the provision of a magazine of the above-described type which can be loaded or unloaded without the necessity for first removing the magazine from th firearm.

Another important object of this invention resides in the provision of a cartridge feeding magazine with the above characteristics wherein the ability thereof to successively advance the cartridges into firing position is not terminated by a failure of one of them to fire.

A final object of the present invention resides in the provision of means for ejecting a cartridge feeding magazine of the above type from the firearm at the will of the operator regardless of whether such magazine is full, partially loaded or completely empty.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings i which:

Fig. l is a side elevational view of the firearm partially broken away to illustrate the interior details of the receiver and magazine;

Fig. 2 is a cross-sectional view taken along line 2-2 in Fig. 1 showing the magazine in the position assumed prior to the firing of the first round;

Fig. 3 is a cross-sectional view taken in the same plane as Fig. 2 but showing the magazine in the position assumed subsequent to the firing of the first round;

Fig. 4 is a cross-sectional view taken in the same plane as Figs. 2 and 3 but showing the magazine subsequent to the firing of all the rounds carried thereby;

Fig. 5 is a fragmentary cross-sectional view taken in the same plane as Fig. 4 but showing the magazine in the position assumed during the removal thereof from the receiver; and

Fig. 6 is an elevational view of the magazine as seen from the rear.

As illustrated in Fig. 1 there is provided a shotgun type of shoulder firearm having a substantially rectangular receiver 10 and a barrel 12 fixedly secured to the for ward end thereof. The bore of barrel 12 is preferably of sufiicient diameter to permit the passage therethrough of relatively large projectiles as, for example, those having a caliber 37 mm. or greater. A substantially rectangular feedway 16 extends transversely through receiver 10 and is completely open at the front end thereof to establish direct communication with the bore of barrel 12.

The floor of feedway 16 is provided with a pair of spaced apart transverse inner tracks 18 straddled by a pair of similarly oriented outer tracks 20 but of lesser width and depth. Tracks 18 and 20 are arranged to slidably receive mating pairs of inner and outer ribs 22 and 24 respectively, depending from the bottom of a substantially rectangular magazine 26 adapted to be inserted into one end of feedway 16 in receiver 10.

Magazine 26 contains a plurality of longitudinal chambers 28 equally spaced apart. in parallel relationship and arranged to hold individual rounds 14 for successive transfer to a firing position as will be more fully explained hereinafter. While the magazine here illustrated shows only three rounds, it should be understood that the number thereof is limited only by practical considerations of weight and size. Each chamber 28, except the last one in the trailing end of magazine 26, is arranged to communicate with the underside of magazine 26 by means of a centrally disposed vertical hole 30. A headed feeler pin 32 is slidably disposed in each hole 30 and is provided with a beveled upper end 31 for movement into and out of the interior of the corresponding chamber. A double-armed lever 34 is pivotally mounted to the underside of magazine 26 between each pair of adjacent chambers 28. One arm of lever 34 is formed with an open groove 35 in the top surface thereof adapted to engage the headed end of feeler pin 32 while the opposite arm of such lever is arranged to contact the exposed end of a spring 38 vertically disposed in magazine 26. As a result of such structure, each lever 34 urges the associated pin 32 into the interior of the corresponding chamber 28 only in the absence of a projectile therein as best shown in Fig. 4.

The opposing faces of inner ribs 22 are each rectangularly slotted so that the opening between such ribs forms a T-slot as best shown at 40 in Fig. 6 which extends along the bottom of magazine 26 from one side to the other. T-slot 40 serves as a passage and retention means for the uncoiled portion of a negator type coil spring 42 having its terminal end securely fastened to the floor of feedway 16 in receiver 10 by suitable means such as the riveting shown at 44 in Fig. 2. The coiled end 46 of negator spring 42 is of greater diameter than the height of T-slot 40 and is, therefore, retained against the trailing end of magazine 26 to provide the bias necessary to successively move each cartridge chamber 28 into axial alignment with the bore of barrel 12.

A vertical passage 48 is centrally provided through the bottom of receiver 10 and extends upwardly through the area between inner tracks 18 to communicate with T- slot 40 in the underside of magazine 26. A cylindrical magazine retaining latch 50 is slidably mounted in passage 48 and is provided with a stepped shoulder 52 on the upper end thereof arranged to successively engage the leading end of each of levers 34 and thereby retain magazine 26 in each of its cartridge firing positions. The portion of latch 50 beyond shoulder 52 is beveled. as shown at 54, to insure the downward movement thereof out of the path of magazine 26 as the latter is being pushed into its operating position in receiver 10. The lower end of latch 50 is of reduced diameter, as indicated at 56, and terminates in a depending threaded portion 58 of even smaller diameter.

The underside of receiver is longitudinally slotted, as shown at 60 in Fig. 1, to a greater width than the diameter of passage 48 and is arranged to seat a mating flat spring 62. The rear end of spring 62 is fixedly secured to the underside of receiver 10 by the same screw 64 utilized to fasten the trigger guard 66 in place. Spring 62 is also centrally provided with a vertical hole 68 through which the threaded end 58 of latch 50 is arranged to project and receive a nut 70. Thus, latch 50 is securely fastened to spring 62 but is capable of vertical movement in hole 68 since the front end of such spring is unsupported to permit bending thereof about screw 64 as a fulcrum.

The required downward movement of latch 50 is obtained by a release lever 72 pivotally mounted in a longitudinally extending recess 74 formed in the underside of receiver 10 forwardly of slot 60. The rear end of release lever 72 is of stepped construction, as shown at 76, in order to lie above the front end of spring 62 when the latter lies in the normal unbowed position.

The trailing end of magazine 26 is provided with an inclined slot 76 the lower end of which is intersected by a horizontal dovetailed groove 78 opening into T-slot 40. A magazine stop 80 is suitably dovetailed on both sides to fit into groove 78 and is fixedly retained therein by a pin 82. Stop 80 extends sufliciently downwardly into T-slot 40 to maintain the uncoiled portion of negator spring 42 in substantially the same plane as the floor of feedway 16 in receiver 10. A horizontally projecting leg 84 is provided on the bottom of stop 80 to engage shoulder 52 on latch 50 and prevent further transverse movement of magazine 26 in receiver 10 after the last cartridge has been fired.

To prepare for operation of the firearm, the end of magazine 26 in which stop 80 is mounted is inserted into feedway 16 in receiver 10. As magazine 26 is pushed against the coiled end 46 of negator spring 42, latch 50 will be cammed downwardly against the resistance of fiat spring 62. Once stop 80 has passed over the top of latch 50, the subsequent upward movement of the latter positions shoulder 52 thereon into blocking engagement with leg 84 on stop 80 thereby retaining magazine 26 in receiver 10 as best shown in Fig. 4. Thereupon, the chambers 28 which extend outwardly of receiver 10 may be loaded with cartridges 14. As the projectile portion of each cartridge is moved forwardly into chamber 28. pin 32 will be cammed downwardly against the corresponding spring-biased double-armed lever 34.

Movement of magazine 26 against the bias of negator spring 42 is then continued until the leading double-armed lever 34 passes over latch 50 for engagement therewith as shown in Fig. 2. The empty chamber 28 above magazine stop 80 is thus exposed and may then be loaded with a cartridge 14. If desired, all the chambers 28 may be loaded before the magazine 26 is inserted into receiver 10 thereby permitting immediate positioning thereof in the initial firing position.

Upon discharge of the leading cartridge 14, the exit of the projectile from the cartridge case which remains in chamber 28 frees headed feeler pin 32 for upward movement into the interior of chamber 28 thereby permitting lever 34 to pivot in response to the urging of vertical spring 38 out of engagement with latch 50. Thereupon, the bias of negator spring 42 advances magazine 26 until the next double-armed lever 34 is engaged by latch 50. This procedure is successively repeated until the stop 80 adjacent the last chamber 28 contacts latch 50 and assumes the position shown in Fig. 4.

In the event one of the cartridges l4 fails to fire. magazine 26 may still be advanced to place the next round in firing position by depressing the forward end of release lever 72 which actuates fiat spring 62 to withdraw latch 50 from engagement with the double-armed le er 34 thereabove as indicated in phantom in Fig. 1. When release lever 72 is actuated after the last cartridge has been discharged, the bias of negator spring 42 will eject the entire magazine 26 from the firearm.

Thus, there is here provided a simple and reliable magazine of rugged construction which is especially well adapted to hold cartridges having relatively large caliber projectiles which are subject to injury if roughly handled. The magazine may be loaded, fired, or unloaded at the will of the operator without the necessity for prior removal thereof from the firearm.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

I claim:

1. A magazine for automatically positioning projectiles into firing position in the receiver of a shoulder operated firearm, said magazine comprising a plurality of chambers for carrying the projectiles, a lever pivotally mounted adjacent each one of said chambers except the one last to be advanced into firing position, a feeler pin slidably mounted in said magazine above one end of each one of said levers, a spring bearing against the opposite end of each of said levers whereby the resulting pivotal movement thereof actuates said corresponding feeler pin to project into the interior of said cham bers in the absence of any projectile therein, a stop fixedly retained in said magazine below said last projectile-carrying chamber in the same relative position thereto as that occupied by said levers and the others of said chambers, latch means slidably mounted in the receiver for successively engaging each of said levers and said stop to locate the projectiles in firing position, and spring means bearing against one end of said magazine for continually urging the latter outwardly of the firearm whereby the upward movement of each of said feeler pins into an empty chamber effects disengagement of the corresponding lever from said latch means and thereby releases said magazine to advance the next successive projectile into firing position.

2. The combination defined in claim 1 including means for manually releasing said latch means from engagement with each of said levers to initiate the same movement as that imparted to said magazine upon the discharge of a projectile therefrom.

3. In a shoulder operated firearm having a receiver, a barrel, and a transverse feedway through the receiver opening forwardly into direct communication with the bore of the barrel, a magazine slidably disposed in the feedway, a plurality of chambers contained in said magazine for holding cartridge case supported projectiles therein, a plurality of feeler pins slidably mounted in the bottom of the magazine to project upwardly into the interior of each one of said chambers other than the trailing one thereof immediately following the exit of a projectile therefrom, a plurality of double-armed levers pivotally secured to the underside of said magazine for engagement with the lower end of said corresponding feeler pin, spring means seated in said magazine for normally urging each lever upwardly against said feeler pin engaged therewith, a fixed stop mounted in said magazine beneath said trailing projectile chamber and having a horizontally projecting leg terminating in alignment with the vertical axis of said chamber thereabove, a latch slidably disposed in the bottom of the receiver for successively engaging said levers and said stop to locate said magazine so that one of said projectile chambers is in firing position, and a negator spring having one end fixedly secured to the floor of said feedway and the other end in coiled form bearing against the trailing end of said magazine for imparting movement thereto in a feeding direction whenever said feeler pin is forced upwardly into the interior of the leading one of said chambers upon the exit of a projec tile therefrom.

4. The combination defined in claim 3 including a fiat spring fixedly secured at one end to the underside of said receiver, means for mounting said latch to said flat spring, and a release lever pivotally attached to the underside of the receiver and having one end thereof extending rearwardly above the free end of said fiat spring whereby manual operation of the free end of said release lever actuates said latch to permit said negator spring to automatically advance said magazine in the feeding direction.

5. In a shoulder operated firearm having a receiver, a barrel, and a transverse feedway extending through the receiver to open forwardly into direct communication with the bore of the barrel, the combination of a magazine having a plurality of equally spaced parallel chambers each arranged to hold a complete round of ammunition consisting of a cartridge case and a forwardly extending projectile, said magazine being of sufiicient width to permit all except one chamber to project exteriorly of the receiver, mating rib and track means in the underside of said magazine and in the floor of the feedway for slidably supporting said magazine in the receiver, the underside of said magazine having a T-slot extending transversely therethrough, a

6 I t feeler pin slidably mounted in said magazine beneath each of said chambers therein except the trailing one thereof, each of said pins having a lower headed end depending into said T-slot and a beveled upper end arranged to project into the interior of said chamber forwardly of the cartridge case in the absence of any projectile therein, spring-biased lever means for continually urging said headed pins upwardly into the interiors of said chambers, a stop fixedly mounted in said magazine beneath said trailing chamber, a latch slidably disposed in the bottom of the receiver to project upwardly into the feedway and successively engage the leading ends of said lever means and said stop for locating said magazine with one of said chambers in firing position, a longitudinally extending flat spring centrally seated in the underside of the receiver and fastened thereto at the rear end thereof, said spring having a hole therethrough for the passage of said latch, and a negator spring having one end fastened to the floor of the feedway and extending along said T-slot in the underside of said magazine to terminate in a coiled end bearing against the trailing end of the latter for automatically imparting movement thereto in the feeding direction whenever the beveled upper end of said feeler pin is forced upwardly into the interior of said chamber upon the exit of a projectile therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 

